The chemical designation is
pyrazino[1',2':1,6]pyrido[3,4-b]indole-1,4-dione,
6-(1,3-benzodioxol-5-yl)2,3,6,7,12,12a-hexahydro-2-methyl-, (6R,12aR)-. It is a crystalline solid that is
practically insoluble in water and very slightly soluble in ethanol.

What are the possible side effects of tadalafil (Adcirca, Cialis)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

If you become dizzy or nauseated during sexual activity, or if you have pain, numbness, or tingling in your chest, arms, neck, or jaw, stop and call your doctor right away. You could be having a serious side effect of tadalafil.

Stop using tadalafil and call your doctor at once if you have any of these serious side effects:

What are the precautions when taking tadalafil (Cialis)?

Before taking tadalafil, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.